Investigation on Hydrogen Storage Using Carbon Nanostructure Materials

Today, hydrogen storage as a clean and renewable energy source has main rule in the energy saving studies. Adsorption of hydrogen molecules on the adsorbent surface is an effective method in this point. In this paper, application of nanostructure carbon metrials such as carbon nanotubes, nanohorns and fullerene molecules in the hydrogen adsorption are investigated. Generally Nanotube carbons have low specific surface area and therefore have low affinity in hydrogen adsorption, but this affinity can improve. Some examples of these improvements are impregnation with metals such as Li, chemical treatment with KOH and heat treatment in temperature 400-500 oC. Nanohorns have higher specific surface area than nanotubes and their surface area can improve to 1900 m2/gr by means of heat treatment. In this condition, hydrogen storage capacity are around 4 wt% at T=77 K. Hydrogen storage of fullerenes improve with both mechanisms of adsorption within molecular structure and hydride formation. In addition, activated carbons produced from fullerene have high adsorption capacity to storage of hydrogen.